Secondary disazo dyestuffs



Patented Mar. 28, 1939 UNITED STATES SECONDARY DISAZO DYESTUFFS CharlesGraenacher, Riehen, Richard Sallmann,

Binningen, and Hans Johner, Basel, Switzerland, assignors to the firm ofSociety of Chemical Industry in Basle, Basel, Switzerland N 0 Drawing.Application November 13, 1937, Se-

rial No. 174,490. In Switzerland November 16,

4 Claims.

It has been found that new azo-dyestuifs can be obtained by couplingcompounds of the general formula in which as stands for a member of thegroup consisting of a diphenyl linkage and a CH2group, and in which thesubstituents of the phenolic nucleus are distributed in sucha mannerthat the para-position to the OH-group is occupied, with suchdiazo-azo-compounds which do not contain Oil-groups in ortho-position tothe diazonium group. Depending on whether or not the diazo-azo-compoundcontains sulfo groups or carboxyl groups, there are thus obtainedwater-soluble or water-insoluble dyestuffs. The former can be used aswool dyestuffs or cotton dyestuffs, the latter are pigments which whenproduced on suitable substrata, dye the same fast tints. Differentshades are obtained according to the selection of thediazo-azo-compounds.

The new azo-dyestuffs correspond therefore to the general formula inwhich R stands for a radical of an azo-dyestuff and a: has thesignification indicated above.

, Among these dyestuffs particularly the waterwith saponifying agents,regenerate the sparingly soluble dyestuffs.

Compounds of the above characterized general formula are for example4-benzyl-phenol, 4- hydroxy diphenyl, 4-hydroxy-3-chlorodiphenyl,4-methyl-2-benzylphenol, 4 5-dimethyl-2*benzylphenol and the like.Diazo-azo-compounds which are particularly suitable are for examplediazoazo-compounds of the benzene or naphthalene series, such as forexample those from aminoazobenzene, aminoazotoluene, 4:4-diamino-2methyl-5-methoxyazobenzene, l-aminonaphthalene- 4-azobenzeneand the like.

The following examples illustrate the invention, the parts being byweight:

Example 1 26.3 parts of 4-amino-3:2'-dimethy1azobenzene hydrochlorideare diazotized in the usual man ner and filtered, if necessary. Thediazonium solution is allowed to drop slowly into a solution consistingof 18.4 parts of 4-benzylphenol in 25 parts by volume of a sodiumhydroxide solution of 30 per cent. strength, parts of 2-nsodiumcarbonate solutionand parts of water. Coupling takes place immediatelywith formation of a brown precipitate. Stirring is continued overnight,the whole is filtered the following morning, and the precipitatethoroughly washed and dried. It is a light brown powder and can berecrystallized with 15 times its quantity of benzene. The productpurified in such a manner melts at 183185 C. The new dyestuif of the CHCH3 formula produces on cotton yellow brown tints.

The following table displays examples of further dyestuifs obtainablewith aid of diazotized The following table displays examples of fur-Diazotizing component Coupling component Dyeing produced on cottonDyestufi 2 of the above table corresponds to zene.4-amino-3:2-dimethylazobenzene the formula ('31 (I) OZHB OIH Dyestuff 17of the above table corresponds to the formula 12.8 parts of4:4-diamino-2'-methyl-5-methoxy-lzl'-azobenzene are stirred with 55parts of cold water and tetrazotized by careful addition of a solutionof 7.2 parts of sodium nitrite in 20 The solution is stirred for afurther hour and filtered, if necessary. It is then slowly dropped intoa solution consisting of 18.4 parts of 4-benzylphenol in 40 parts byvolume of a sodium hydroxide solution of 30 per cent. strength, 50 partsof 2 n-sodium carbonate solution and 500 parts of water. placeimmediately with formation of a brown Stirring is continued overnight,whole is filtered and the precipitate thoroughly washed and dried. Thereare thus obtained 25 parts of a dark brown powder which can be repartsof water.

precipitate.

OCH;

Example 2 crystallized from chlorobenzene (4 parts).

melts at 199-201 C. and produces on cotton red- Coupling takes3-chloro-4-oxydiplienyl 4-methyl2-ben'zylphenol diamines Z Yellowishorange.

Reddish brown.

Red yellow.

Reddish brown.

Yellowish brown.

Orange brown.

Red brown.

Do. Do. Yellow brown.

o. Reddish brown.

Yellowish brown. 20

ther dyestuffs obtainable with aid of tetrazotized Diazotizing componentCoupling com- 1 4:4-dia1nino 2 methyl 5nethoxyazobenzene.

4-hydroxydiphenyl Reddish brown.

3- chloro-4 hydroxydiphenyl.

4 methyl 2 benzylphenol.

3 bromo 4 hydroxydiphenyl.

of water.

water. the

dish brown tints. The new dyestuff corresponds to the formula produceson cotton violet brown tints.

Example 3 45 17.8 parts of 4'-chloro-2-nitrophenyl-1:1'-azo-3-methoxy-4-aminonaphthalene are stirred with 150 parts of aceticacid of per cent. strength. There are then carefully added 15 parts ofconcentrated hydrochloric acid and a solution of 3.6 parts of sodiumnitrite in 10 parts After hour the suspension of the diazo compound thusformed is allowed to run into a solution of 9.2 parts of 4-benzylphenolin 15 parts by volume of a sodium hydroxide solution of 30 per centstrength and parts of Coupling takes place immediately with formation ofa precipitate. overnight, the whole is then filtered and the precipitatethoroughly washed and dried. The dyestufi is obtained as a dark powderwhich can be recrystallized from 5 parts of chlorobenzene. The newdyestuff of the formula Stirring is continued OOH; OH

Similar 75 tints are obtained with the azo-dyestuff from 4-aminonaphthalene-l: 1'-azo-naphthalene.

Example 4 99 parts of a 4-amino-1:1-azobenzene-3:4'- disulfonic acid of36 per cent. strength are dissolved in 750 parts of warm water, and tothis solution there are added '7 parts of sodium nitrite and about 400parts of ice, and then, while quickly stirring, 30 parts of concentratedhydrochloric acid. After hour the clear solution is allowed to run intoa solution consisting of 18.4 parts of 4-benzylphenol in 20 parts of a10 times normal caustic soda solution, 2 parts of sodium carbonate and250 parts of water. Coupling takes place immediately with formation of abrown precipitate. Stirring is continued over night and the dyestufi issalted out with common salt. It is a dark brown powder which dissolvesin water to a dark brown solution and dyes wool from an acid bath brownyellow tints. The new dyestuff corresponds to the formula The followingtable also displays examples of further dyestuffs and their tinctorialproperties:-

2. The azo-dyestufls of the general formula in which R1 and R2 stand formonocyclic aromatic nuclei, one azo-group stands in l-position and theother stands in 4-position to the radical R2, and ac stands for a memberof the group consisting of a diphenyl linkage and a CH2group, whichproducts are free from sulfo groups and carboxyl groups.

3. The azo-dyestufis of the general formula in which R1 and R2 stand formonocyclic aromatic nuclei, one azo-group stands in l-position and theother stands in 4-position to the radical R2, which products are freefrom sulfo groups and carbo-xyl groups.

Diazotizing component 52 5 5 Dyestufi Solution Dyeing on wool 14-amino-1:1-azobenzene-3:4-disulionic acid 4-hydroxydiphen- Dark brown.Brown Yellow brown.

2 4-amino-1:l-azobenzene-4-sulfonic acid 4-benzylphenol- Brown -doOrange brown. 3 4-l11ydroxydiphen- Dark brown. do Yellow brown.

y 4 4 amino 3:2 dimethyl 1:1-azobenzene 4 4-benzylphenol Brown Lightbrown Brown yellow.

sulfonic acid. 5 n 4-hlydroxydiphen- Dark brown. Brown Yellow brown.

What we claim is:- 1. The azo-dyestufis of the general formula 4. Theazo-dyestuffs of the general formula GHQ in which R1 and R2 stand formonocyclic aromatic nuclei, one aZo-group stands in l-position and theother stands in l-position to the radical R2, which products are freefrom sulfo groups and carboxyl groups.

CHARLES GRAENACHER. RICHARD SALLMANN. HANS J OI-DTER.

